Selective switch.



T. H. NELSON.

SELECTIVE SWITCH.

APPLICATION FILED ms. 12. 1911.

Patented Dec. 2.1919.

Chicago, in the county Minn-mm rnnonoan n. sin-Leon,

PATENT ()FFIOE.

or cmcaco; memo 1s.

sELncrivn SWITCH.

sesame.

'Specification of Letters Patent.

- Patented Dec. 2,1919.

Gifiginal application filed Eanuary $39, 1916,,Sc1'ia1 No. 74,982; "Divided and this application filed February renew. Serial No. mess.

To all whom may concern:

Be it known that l, Tiinooonn Nnnso s, a citizen of the United States, residing of Cook and State of Illinois, have invented a new and limprovcd Selective Switch, of which the following is a specification.

, My invention relates to an improved con struction cit switching mechanism for use in selectively" controlling a plurality of circuits, so that-by the operationof the same devices anyone of a desired number :of circuits maybe selected and closed. I am aware that selective switching mechanism of this class has been constructed heretofore injthe art and I do not, therefore, broadly claiin' such a switching mechanism as my invention, but, on'the other hand, my invention consists in a particular construction of suchswitching mechanisms by which a single element or device, which may have the form of'a circular dial, is employed to select the circu t to be controlled. by rota ing t he-dial, and the closure of the circuit is efiected by moving the dial longitudinally upon-Hts axis. The switching mechanism is preferably provided with a metallic casing iconstructed so that it'inay be used in exposed locations without danger oi the switching mechanism becoming disturbed. or deranged and. 1 preferably employ in the casing safety contacts so that if an. attempt is made to open the casing b an' unauthorizecl person, the safety contacts ma" control the closure of an alarm circuit to indicate the tampering;

My invention is particularly adapted for use in connection with my burglar :1 arm.

system, constituting the subject matter of co-pending application, Serial No 7%,962, filed J anuaryfill, 1916, of which application this is a divisional application.

My invention will best be understood by reference to the accompanying drawings in 'which-- Figure 1 shows in a vertical sectional. view the detail construction oi the switching mechanism, I

Fig. 2 shows the switching mechanism in front elevation, v

Fig. 3 shows'the switching mechanism in. rear elevation with the casing removed, and

Fig. shows the switching mechanism in front elevation with the front plate removed.

on its Similar numerals refer to similar &

throughout the several views.

In these figures the casing 10, which is cyl ndrical in form, issecured by screws as indicated to the front plate 11 which supports by a plurality of posts-12 the insulating disk" 13 which constitutes the support for the contacts 14 and conducting ring 15, these contacts and conducting iv being located on the front side of the d The front plate 11 has extending 3 rwardly from it a central boss 16 in which a cylindrical rod 17 is mounted so as to be freely rotatable. 'The inner end of the rod 17 has mounted upon it a contact blade 18 which is secured in place between a collar 19 and nut 20 carried by'saidrod. One end of the contact blade 18 is arranged to engage the contact ring 15 and the other end of said blade is arranged to engage sired ones of the contacts 14-, the conducting ring and contacts being in difiercnt planes so that the contact engaging end oi? the contact blade does not engage the conducting ring: in its normal position the contact blade 15% is held away from the contacts and conduct mg ring by a spring 21 located in a suitable recess in the front plate '11 between said plate and the inner face of the dial 22 rigidly secured to the outer end of the rod 252 is formed into a hub 23 by which the dial may be rotated At its outer edge the dial has an inwardly extending flange 24 to increase the bearing surface between it and the cylindrical bore formed therefor in the front plate 11. The flange 24 has projecting rearwardly from it a pin 25 for entering the h les "26 formed in the front plate to permit the dial to be pushed rearwardly only when the contact blade 18 is angularly alincd with desired ones of the contacts 14-.

The edge ot the dial'and the adj acent edge of th front plate are provided with graduzv tions and suitable indications as, for exam ple, numbers, so that the dial, rod and contact blade may be turned to bring the contact blade opposite any desired contact 1h tor which condition, as result of the co operation of the pin 25 with the correspond ing one of the holes 26, the dial may lsc pushed rearwardly against the action of the spring 21 to bring the contact blade 18 into engagement with the selected contact 1 and at the same time with the conducting ring 'bontacbs on the Contact supporting ghte 23161 a; switch bmde carried by said #:o out Contact with the contacts on the Contact sup porting plate, whereby angular motion 0% said rod and switch blade selects a desired Contact and longitudinal motion of said rod -"0nnects said switch blade with said Contact, 1

said front plate having a circular m its outer sm'face, a disk carried by the outer end of said rod inclosing, said recess, azz registering devices "beiween said disk and said front plate comprising a pin carriefi by =spring iending to hold said rod in its out position. 

